Various vehicular or stationary enclosures are designed to protect occupants from injury due to an explosion adjacent the enclosures. Often, these enclosures incorporate armor (e.g., iron plate, rolled steel, and synthetic materials such as para-aramid synthetic fiber, Ultra-high-molecular-weight polyethylene, and various ceramics, or any combination thereof) to achieve the desired level of protection. The type and thickness of the armor is often chosen to protect occupants from an expected maximum explosion energy.
However, due to the fragile nature of the human body, even when the armor is strong enough to withstand an explosion, occupants inside an enclosure may still be injured from overpressure waves transmitted through breaches in the enclosure, open windows or doors in the enclosures and/or directly through the enclosure outer bounds (e.g., through the walls, floor, ceiling, doors, windows, etc.) against air trapped within the enclosure. Many enclosures include devices to relieve this overpressure (e.g., doors that blow off or an opening with a plug that blows out of the enclosure). However, the overpressure relief devices may not have immediate effect, especially during a critical period immediately after the explosion when the overpressure waves may echo and rebound within the confines of the enclosure. The primary and echoed waves can reinforce one another and create greater overpressure waves that can further injure the occupants of the enclosures by causing damages to soft tissues (e.g., brain concussions). Further, the overpressure waves may also cause rapid changes in the enclosure outer bounds that are in contact with the occupants, which can further injure the occupants. Injuries such as broken bones may occur by due to a rapid change in the user's position adjacent the enclosure outer bounds.
As a result, armor is often over designed to prevent any deflection and/or breach of the enclosure and prevent overpressure waves from traveling through the enclosure. However, overdesign of armor results in rapidly increasing weight and cost. As a result, present armor types and combinations are ill equipped to prevent injuries to occupants of the enclosures caused by overpressure waves and/or deflections of the enclosure within cost and weight constraints.